The ZSI 127 train control system monitors the movement of the train using dynamic braking curve computation. The basic functionality has been enhanced with special functions for operation on secondary lines.

Data is transmitted on an intermittent basis via Eurobalises, and also semi-continuously via Euroloop if necessary. The movement of the train is monitored continuously and without interruption on the basis of braking curve computations. Intervention happens in stages, starting with an audible warning, followed by service braking and, if necessary, emergency braking. Functions that are supplementary to ETCS are programmed in the systemspecific telegram packet 44. This provides interoperability on ETCS Level 1 tracks.

The use of ETCS components and processes means that any investment in this system is protected into the future.

Vehicle Equipment
The vehicle equipment, consisting of the Simis Train Control Computer, the operating and display unit and the ETCS vehicle antenna, all have a compact design and are manufactured to be extremely robust. This allows them to be installed in the vehicle without difficulty, even where space is limited.

Track Equipment
The track equipment, consisting of Leu S21 M, Eurobalise S21 and Euroloop S21, is identical to ETCS Level 1 equipment. Only the installation guidelines (rack-rail applications) partly differ from the ETCS rules. If the installation complies with ETCS guidelines, mixed operation with ETCS Level 1 and ZSI 127 is possible on the relevant tracks.